Fractures of the femoral neck at the hip joint are one of the most frequent fractures in elderly women, the result of osteoporosis, the thinning of bone tissue and the loss of bone density. The blood supply to the head of the femur is very precarious, and it tends to become more so as one gets older, and as a result, a good percentage of the hip fractures of the elderly will not heal regardless of the method of treatment. Because of this dilemma, many surgeons elect to not try to heal the fracture, but instead, replace the head of the bone with a prosthesis. While this arthroplasty may function sufficiently well for the older, more sedentary patients, it may not be adequate for the needs of younger more active patients, as it may wear and become painful to the point where further surgery such as total hip replacement may become necessary. To avoid this outcome in this large group of patients, internal fixation surgery to promote healing of the fracture is desirable in certain types of hip fractures. Unfortunately, the currently available means to secure femoral neck fracture fixation are not without significant disadvantages. It has been found that while the use of multiple threaded pins for fixation results in less osteonecrosis of the head of the femur, they result in more non-unions than do sliding compression screws which result in more unions but also cause an increase in the death of the head, probably because of the greater intramedullary vascular damage as a result of wider reaming. These facts would suggest that an increase in the effective rigidity of the multiple threaded hip pins would lead to an increase in the number of unions, and a decrease in the number of femoral head deaths in many patients.
Among the devices used, the earliest where rods or lag screws inserted from the lateral cortex of the femur into the head. Problems with these led to the use of bone plates fastened to their base and fixed to the lateral cortex. Further developments included rods or lag screws with tubular collars that permitted the screw to slide out to compensate for shortening of the neck as healing took place. Also used where multiple threaded pins, some using a cortical side plate in conjunction with the pins to help stabilize them, others using a cortical side plate with elongated pin collars. Unfortunately, pins used in this manner still behave as long cantilevered springs, with little or no support in the osteoporotic neck of the femur, resulting in a lack of complete immobilization of the fracture, and a resulting non-union. Further developments led to the use of single or multiple hip screws supported by intramedullary rods inserted into the medullary canal of the femur from its proximal end. These often used an outrigger type of drill jig attached to the proximal end of the intramedullary rod to drill the openings for, and guide the screws alongside of, or in some instances, through orifices in the rods into the head of the femur. Because of the shaft/neck angle, they do little to support the more distal pins. These devices using an intramedullary rod add yet another element of risk to an already fragile elderly patient with the more extensive surgery, blood loss and anesthesia time required. In addition, the large opening made near the base of the neck of the femur to accommodate the rod could further interfere with the already precarious blood supply to the head and neck of the femur.